From the Summary: "Stop Loss is a frequently misunderstood DOD force management program that retains servicemembers beyond their contractually agreed-to separation date. Because of the involuntary nature of this extension, some critics have referred to the program as a 'backdoor draft' or 'involuntary servitude'. Stop Loss was initially used the 1990-91 Gulf War and later in Bosnia and the Kosovo Air Campaign. All of the Services used Stop Loss at the beginning of Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) but only the Army has consistently employed some form of Stop Loss over the past five years. Today, there are over 12,000 soldiers in the active Army, Army Reserve and Army National Guard who remain on active duty beyond their scheduled separation date as a result of Stop Loss. [...]. In January, 2007 the newly appointed Secretary of Defense Gates directed the Services to minimize the use of Stop Loss. The Army has consistently argued that Stop Loss is necessary to ensure that only trained and ready units are deployed to Iraq and Afghanistan. Today, DOD officials concede that the Army will need to continue using Stop Loss, probably at least through 2009 or longer. With its continued use by the Army and the recent establishment of a special pay, it is anticipated that Stop Loss will be of significant and continuing interest to the 111th Congress."
CRS Report for Congress, R40121